There are demands for controlling the appearance of surfaces, such as glass windows. Such demands arise from needs for privacy, e.g., in urban environments. Such demands also arise from needs for personalization, e.g., in home and business environments. These demands have traditionally been met using manual approaches.
For example, to control the amount of indirect light through a glass window, window coverings have been used. While window coverings, such as blinds and curtains, may be used to alter the light allowed through a window temporarily, the use of such coverings requires manual manipulation, which may be cumbersome. Other attempts have involved manually tinting the glass. However, glass tinting is permanent and does not readily allow for change.
There have been other attempts to change the appearance of a window or a glass surface using electronic circuits within the surface to change the electrical properties of the surface. However, such circuits are not easily sustainable and are prohibitively expensive. Also, this approach is not readily applicable to legacy systems, as it would require the installation of new windows or glass including the electronic circuits to change the electrical properties of the surface.